They might not be on our coat of arms, but the Australian koala is an iconic animal high on the list things for tourists to see when visiting the Hunter region.

And, according to the experts, koalas are also an important sign that humans atre doing the right thing by the environment.

This week Conservation Volunteers Australia [CVA] and Port Stephens Council will plant thousands of trees to restore koala habitat, and improve the water quality of the Hunter River.

Some of that work is being done by backpackers from Korea and Germany who - only last week - patted a koala at Blackbutt Reserve for the very first time.

Environmental officer for Port Stephens Council Lincoln Carter says koalas are 'a key species for conservation' and 'an indicator of healthy environmental systems'.

"If you're preserving koala habitat and the koala, you're going to be improving habitat for a myriad of other species,' Mr Carter said.

Planting 4,000 trees on private farm land fronting Windeyers Creek will also improve water quality for recreational users, improving the filtration of farming-related substances like fertiliser and animal faeces.

"Restoring the riparian vegetation along the river here, just before it enters the Hunter River, will improve the quality of water coming from Windeyers Creek," Mr Carter said.

Volunteers working on the tree planting this week include backpackers from Germany and Korea.

Lisa Burand, visiting Newcastle from Germany, is enjoying the work as part of a year-long working holiday around Australia.

She has also taken part in CVA projects in Bathurst, Orange, Mudgee, Dubbo.

"Sometimes we work for farmers and they are really friendly - we have had barbecues," she said.

Ms Burand, who patted her very first koala in Newcastle this week, has a general interest in environmental work and hopes to study english and art when she returns to Germany.

She now hopes to Raymond Terrace in 10 to 15 years' time to see how her work has progressed.

"I think my aim now is to do that!" she says.

Team leader of the CVA volunteers Craig Whitford says tree planting is win for everyone.

"It's not only improving the environment, but it's improving the surrounding farmland, by creating areas for wildlife corridors, for kolas and possums and smaller animals," he said.

Mr Whitford said it helps to control the wind and the water flow through the area, 'which is of benefit to the farmer himself'.

"It's still a useable farm and [the farmer] is still running cattle and growing vegetables on the farm as we speak," Mr Whitford said.

1233 ABC Newcastle approached the land owner for a comment for this story, but he declined to speak.

According to Mr Carter the land owner - whose family has had a connection with the property for generations - was motivated to take part in the tree planting out of a desire to provide koala habitat.

Mr Carter says, apart from altruistic motives, there is little financial incentive for farmers to restock trees on properties.

"This is done by a farmer who is environmentally minded," he said.

"All the labour is paid for, and the trees, but there's no yearly income from this sort of thing; and there is a really good community and environmental benefit from it.

"What would be really good is to have some sort of carbon trading scheme where farmers who want to do this sort of thing are paid for the carbon credits that they're storing by doing these plantings.

"It would be a small income, but it would be an income that would be a yearly thing on their property, and would cover things like their rates for the smaller properties."